Virtual search spaces for beam indication

ABSTRACT

Methods, systems, and devices for wireless communications are described. A base station may identify time and frequency resources for a physical downlink shared channel (PDSCH) to be transmitted to a user equipment (UE) in a first transmission time interval (TTI). The base station may transmit configuration information for a control channel search space set in a second TTI. The second TTI may precede the first TTI. The configuration information may include an indication of an absence of a physical downlink control channel (PDCCH) transmission to send in the control channel search space set indicating the identified time and frequency resources for the PDSCH, and a set of time and frequency resources for the control channel search space set. The UE may receive the configuration information and identify the time and frequency resources allocated for the PDSCH in the second TTI, and receive the PDSCH transmission in the second TTI.

CROSS REFERENCES

The present Application for Patent is a Divisional of U.S. patentapplication Ser. No. 16/267,298 by Nam, et al., entitled, “VIRTUALSEARCH SPACES FOR BEAM INDICATION” filed Feb. 4, 2019, which claims thebenefit of U.S. Provisional Patent Application No. 62/710,486 by NAM, etal., entitled “VIRTUAL SEARCH SPACES FOR BEAM INDICATION,” filed Feb.16, 2018, assigned to the assignee hereof, and expressly incorporated byreference in its entirety.

BACKGROUND

The following relates generally to wireless communication, and morespecifically to virtual search space sets for beam indication.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such asLong Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, orLTE-A Pro systems, and fifth generation (5G) systems which may bereferred to as New Radio (NR) systems. These systems may employtechnologies such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal frequency division multiple access (OFDMA), or discreteFourier transform-spread-OFDM (DFT-S-OFDM). A wireless multiple-accesscommunications system may include a number of base stations or networkaccess nodes, each simultaneously supporting communication for multiplecommunication devices, which may be otherwise known as user equipment(UE).

A base station may send control transmissions (e.g., downlink controlinformation (DCI) via a physical downlink control channel (PDCCH) to theUE. The UE may be configured to monitor a PDCCH within a search spaceset, which may include multiple search candidates. For instance, eachsearch space set may be associated with one or more control resourcesets (coresets) containing multiple control channel elements (CCEs). TheUE may be configured to monitor one or more search candidates in thesearch space set, and may blindly decode the one or more CCEs of thesearch candidate to receive the control information.

SUMMARY

The described techniques relate to improved methods, systems, devices,or apparatuses that support virtual search space sets for beamindication. In some wireless communications systems, a base station mayconfigure and provide a search space configuration. The base station maytransmit control information to a user equipment (UE) within aconfigured search space set. The search space set may be associated withone or more control resource sets (coresets) containing multiple controlchannel elements (CCEs). The base station may transmit the controlinformation in search candidates (e.g., physical downlink controlchannel (PDCCH) candidates) on different aggregation levels within thecoresets. In some cases, the base station may additionally transmit anindication of the search space configuration to the UE. The UE maymonitor for a channel (e.g., a PDCCH) carrying downlink controlinformation (DCI) from the base station according to the search spaceconfiguration.

The UE may detect and decode the DCI within the search candidates in thesearch space set. In some cases, the UE may receive transmissions fromthe base station according to the search space configuration andscheduling information. The DCI may include scheduling information,e.g., resource allocations for transmitting from the base station (andreceiving at the UE) a downlink data transmission (e.g., on a physicaldownlink shared channel (PDSCH)). In some cases, the UE may receive thePDCCH on a first beam during a first transmission time interval (TTI)and the PDSCH on the same beam during a second TTI based on the searchspace configuration and scheduling information. In some cases, the UEmay recognize that certain criteria have not been met (e.g., the timeoffset from the PDCCH to the PDSCH is less than a threshold number ofTTIs) and use a beam of a default configuration, which may be a secondbeam different than the first beam. The search space configuration usedby the UE may be a virtual search space set or a normal search spaceset. A number of actually transmitted PDCCH may be zero for the virtualsearch space set and/or the normal search space set. In some cases, thevirtual search space set may additionally, or alternatively, haveindicated (e.g., by a configuration indication) that a number ofcandidate PDCCHs is zero. As such, the UE may refrain from performing(e.g., by not performing) blind decoding during a TTI associated withthe virtual search space set. The UE may also use the indicated coreset(e.g., time and frequency resources) associated with the virtual searchspace set as the coreset/time and frequency resources for receiving thePDSCH.

A method of wireless communication is described. The method may includereceiving, from a base station, configuration information for a controlchannel search space set in a first TTI, the received configurationinformation including an indication of an absence of a PDCCHtransmission in the control channel search space set, and a set of timeand frequency resources for the control channel search space set,identifying time and frequency resources allocated for a PDSCH in asecond TTI based on the set of time and frequency resources for thecontrol channel search space set in the first TTI and the indication ofthe absence of a PDCCH transmission in the control channel search spaceset, and receiving a PDSCH transmission in the second TTI using theidentified time and frequency resources.

An apparatus for wireless communication is described. The apparatus mayinclude a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe executable by the processor to cause the apparatus to receive, from abase station, configuration information for a control channel searchspace set in a first TTI, the received configuration informationincluding an indication of an absence of a PDCCH transmission in thecontrol channel search space set, and a set of time and frequencyresources for the control channel search space set, identify time andfrequency resources allocated for a PDSCH in a second TTI based on theset of time and frequency resources for the control channel search spaceset in the first TTI and the indication of the absence of a PDCCHtransmission in the control channel search space set, and receive aPDSCH transmission in the second TTI using the identified time andfrequency resources.

Another apparatus for wireless communication is described. The apparatusmay include means for receiving, from a base station, configurationinformation for a control channel search space set in a first TTI, thereceived configuration information including an indication of an absenceof a PDCCH transmission in the control channel search space set, and aset of time and frequency resources for the control channel search spaceset, identifying time and frequency resources allocated for a PDSCH in asecond TTI based on the set of time and frequency resources for thecontrol channel search space set in the first TTI and the indication ofthe absence of a PDCCH transmission in the control channel search spaceset, and receiving a PDSCH transmission in the second TTI using theidentified time and frequency resources.

A non-transitory computer-readable medium storing code for wirelesscommunication is described. The code may include instructions executableby a processor to receive, from a base station, configurationinformation for a control channel search space set in a first TTI, thereceived configuration information including an indication of an absenceof a PDCCH transmission in the control channel search space set, and aset of time and frequency resources for the control channel search spaceset, identify time and frequency resources allocated for a PDSCH in asecond TTI based on the set of time and frequency resources for thecontrol channel search space set in the first TTI and the indication ofthe absence of a PDCCH transmission in the control channel search spaceset, and receive a PDSCH transmission in the second TTI using theidentified time and frequency resources.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for refraining fromperforming blind decoding in the control channel search space set basedon receiving the indication of the absence of the PDCCH transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the configuration informationfor the control channel search space set may be received in radioresource control signaling.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the configuration informationincludes a control resource set configuration from the base station, atransmission configuration indication (TCI) state, and the time andfrequency resources corresponding to resources of the control resourceset configuration.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, in a fieldof a DCI, a transmission configuration indication (TCI) state, where theTCI state includes a spatial quasi-collocation (QCL) parameter for abeam indication.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, in a fieldof a DCI, a transmission configuration indication (TCI) state, andreceiving, based on a scheduling offset of the PDSCH transmission beinggreater than or equal to a threshold value, the PDSCH transmission inthe identified time and frequency resources using a beam associated withthe received TCI state.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, in a fieldof a DCI, a first transmission configuration indication (TCI) state, andreceiving, based on a scheduling offset of the PDSCH transmission beingless than or equal to a threshold value, the PDSCH transmission in theidentified time and frequency resources using a first beam associatedwith a second TCI state, the first beam different from a second beamassociated with the first TCI state, and the second TCI state of acontrol resource set associated with the control channel search spaceset.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the control channel searchspace set associated with a control resource set includes a zero numberof PDCCH candidates.

A method of wireless communication is described. The method may includeidentifying time and frequency resources for a PDSCH to be transmittedto a UE in a first TTI, transmitting, to the UE, configurationinformation for a control channel search space set in a second TTI, thesecond TTI preceding the first TTI, and the configuration informationincluding an indication of an absence of a PDCCH transmission to be sentin the control channel search space set to indicate the identified timeand frequency resources for the PDSCH, and a set of time and frequencyresources for the control channel search space set, and transmitting aPDSCH transmission in the first TTI using the identified time andfrequency resources for the PDSCH.

An apparatus for wireless communication is described. The apparatus mayinclude a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe executable by the processor to cause the apparatus to identify timeand frequency resources for a PDSCH to be transmitted to a UE in a firstTTI, transmit, to the UE, configuration information for a controlchannel search space set in a second TTI, the second TTI preceding thefirst TTI, and the configuration information including an indication ofan absence of a PDCCH transmission to be sent in the control channelsearch space set to indicate the identified time and frequency resourcesfor the PDSCH, and a set of time and frequency resources for the controlchannel search space set, and transmit a PDSCH transmission in the firstTTI using the identified time and frequency resources for the PDSCH.

Another apparatus for wireless communication is described. The apparatusmay include means for identifying time and frequency resources for aPDSCH to be transmitted to a UE in a first TTI, transmitting, to the UE,configuration information for a control channel search space set in asecond TTI, the second TTI preceding the first TTI, and theconfiguration information including an indication of an absence of aPDCCH transmission to be sent in the control channel search space set toindicate the identified time and frequency resources for the PDSCH, anda set of time and frequency resources for the control channel searchspace set, and transmitting a PDSCH transmission in the first TTI usingthe identified time and frequency resources for the PDSCH.

A non-transitory computer-readable medium storing code for wirelesscommunication at is described. The code may include instructionsexecutable by a processor to identify time and frequency resources for aPDSCH to be transmitted to a UE in a first TTI, transmit, to the UE,configuration information for a control channel search space set in asecond TTI, the second TTI preceding the first TTI, and theconfiguration information including an indication of an absence of aPDCCH transmission to be sent in the control channel search space set toindicate the identified time and frequency resources for the PDSCH, anda set of time and frequency resources for the control channel searchspace set, and transmit a PDSCH transmission in the first TTI using theidentified time and frequency resources for the PDSCH.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting theconfiguration information for the control channel search space set usingradio resource control signaling.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the configuration informationincludes a control resource set configuration, a transmissionconfiguration indication (TCI) state, and the time and frequencyresources corresponding to resources of the control resource setconfiguration.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, in afield of a DCI, a transmission configuration indication (TCI) state,where the TCI state includes a spatial quasi-collocation (QCL) parameterfor a beam indication.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, in afield of a DCI, a transmission configuration indication (TCI) state, andtransmitting, based on a scheduling offset of the PDSCH transmissionbeing greater than or equal to a threshold value, the PDSCH transmissionin the identified time and frequency resources using a beam associatedwith the transmitted TCI state.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, in afield of a DCI, a first transmission configuration indication (TCI)state, and transmitting, based on a scheduling offset of the PDSCHtransmission being less than or equal to a threshold value, the PDSCHtransmission in the identified time and frequency resources using afirst beam associated with a second TCI state, the first beam differentfrom a second beam associated with the first TCI state, and the secondTCI state of a control resource set associated with the control channelsearch space set.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the control channel searchspace set associated with a control resource set includes a zero numberof PDCCH candidates.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 illustrate examples of a wireless communications systemthat supports virtual search space sets for beam indication inaccordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a configuration that supports virtualsearch space sets for beam indication in accordance with aspects of thepresent disclosure.

FIG. 4 illustrates an example of a process flow that supports virtualsearch space sets for beam indication in accordance with aspects of thepresent disclosure.

FIGS. 5 through 7 show block diagrams of a device that supports virtualsearch space sets for beam indication in accordance with aspects of thepresent disclosure.

FIG. 8 illustrates a block diagram of a system including a UE thatsupports virtual search space sets for beam indication in accordancewith aspects of the present disclosure.

FIGS. 9 through 11 show block diagrams of a device that supports virtualsearch space sets for beam indication in accordance with aspects of thepresent disclosure.

FIG. 12 illustrates a block diagram of a system including a base stationthat supports virtual search space sets for beam indication inaccordance with aspects of the present disclosure.

FIGS. 13 through 19 illustrate methods for virtual search space sets forbeam indication in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

A base station may transmit control information to a user equipment (UE)within a configured search space set. The search space set may includeone or more control resource sets (coresets) containing multiple controlchannel elements (CCEs). The base station may transmit the controlinformation in search candidates (e.g., physical downlink controlchannel (PDCCH) candidates) on different aggregation levels within thecoresets. In some cases, the base station may additionally transmit anindication of the search space configuration to the UE. The UE maymonitor a channel (e.g., a PDCCH) for downlink control information (DCI)from the base station according to the search space configuration.

The UE may detect and decode the control information within the searchcandidates. In some cases, the UE may receive transmissions from thebase station according to the search space configuration. The DCI mayinclude schedule and resource allocations for transmitting from the basestation (and receiving at the UE) a downlink data transmission (e.g., ona physical downlink shared channel (PDSCH)). In some cases, the UE mayreceive the PDCCH on a first beam during a first transmission timeinterval (TTI) and the PDSCH on a second beam during a second TTI basedon the search space configuration. The search space configuration may beassociated with a virtual search space set (corresponding to zero PDCCHcandidates configured to be in the search space set) or a normal searchspace set (corresponding to one or more PDCCH candidates configured tobe in the search space set).

Aspects of the disclosure are initially described in the context of awireless communications system. Aspects of the disclosure are furtherillustrated in the context of a configuration and process flow. Aspectsof the disclosure are further illustrated by and described withreference to apparatus diagrams, system diagrams, and flowcharts thatrelate to virtual search space sets for beam indication.

FIG. 1 illustrates an example of a wireless communications system 100that supports virtual search space sets for beam indication inaccordance with various aspects of the present disclosure. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. In some examples, the wireless communications system100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A)network, an LTE-A Pro network, or a New Radio (NR) network. In somecases, the wireless communications system 100 may support enhancedbroadband communications, ultra-reliable (e.g., mission critical)communications, low latency communications, or communications withlow-cost and low-complexity devices.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Base stations 105 described herein mayinclude or may be referred to by those skilled in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation Node B orgiga-nodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or some other suitable terminology. The wirelesscommunications system 100 may include base stations 105 of differenttypes (e.g., macro or small cell base stations). The UEs 115 describedherein may be able to communicate with various types of base stations105 and network equipment including macro eNBs, small cell eNBs, gNBs,relay base stations, and the like.

Each base station 105 may be associated with a particular geographiccoverage area 110 in which communications with various UEs 115 issupported. Each base station 105 may provide communication coverage fora respective geographic coverage area 110 via communication links 125,and communication links 125 between a base station 105 and a UE 115 mayutilize one or more carriers. Communication links 125 shown in thewireless communications system 100 may include uplink transmissions froma UE 115 to a base station 105, or downlink transmissions from a basestation 105 to a UE 115. Downlink transmissions may also be calledforward link transmissions while uplink transmissions may also be calledreverse link transmissions.

The geographic coverage area 110 for a base station 105 may be dividedinto sectors making up only a portion of the geographic coverage area110, and each sector may be associated with a cell. For example, eachbase station 105 may provide communication coverage for a macro cell, asmall cell, a hot spot, or other types of cells, or various combinationsthereof. In some examples, a base station 105 may be movable andtherefore provide communication coverage for a moving geographiccoverage area 110. In some examples, different geographic coverage areas110 associated with different technologies may overlap, and overlappinggeographic coverage areas 110 associated with different technologies maybe supported by the same base station 105 or by different base stations105. The wireless communications system 100 may include, for example, aheterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different typesof base stations 105 provide coverage for various geographic coverageareas 110.

The term “cell” refers to a logical communication entity used forcommunication with a base station 105 (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-Things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area 110 (e.g., a sector) over whichthe logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile device, a wireless device, a remote device, ahandheld device, or a subscriber device, or some other suitableterminology, where the “device” may also be referred to as a unit, astation, a terminal, or a client. A UE 115 may also be a personalelectronic device such as a cellular phone, a personal digital assistant(PDA), a tablet computer, a laptop computer, or a personal computer. Insome examples, a UE 115 may also refer to a wireless local loop (WLL)station, an Internet of Things (IoT) device, an Internet of Everything(IoE) device, or an MTC device, or the like, which may be implemented invarious articles such as appliances, vehicles, meters, or the like.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines (e.g., via Machine-to-Machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay that information to acentral server or application program that can make use of theinformation or present the information to humans interacting with theprogram or application. Some UEs 115 may be designed to collectinformation or enable automated behavior of machines. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, but nottransmission and reception simultaneously). In some examples half-duplexcommunications may be performed at a reduced peak rate. Other powerconservation techniques for UEs 115 include entering a power saving“deep sleep” mode when not engaging in active communications, oroperating over a limited bandwidth (e.g., according to narrowbandcommunications). In some cases, UEs 115 may be designed to supportcritical functions (e.g., mission critical functions), and the wirelesscommunications system 100 may be configured to provide ultra-reliablecommunications for these functions.

In some cases, a UE 115 may also be able to communicate directly withother UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device(D2D) protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a basestation 105. Other UEs 115 in such a group may be outside the geographiccoverage area 110 of a base station 105, or be otherwise unable toreceive transmissions from a base station 105. In some cases, groups ofUEs 115 communicating via D2D communications may utilize a one-to-many(1:M) system in which each UE 115 transmits to every other UE 115 in thegroup. In some cases, a base station 105 facilitates the scheduling ofresources for D2D communications. In other cases, D2D communications arecarried out between UEs 115 without the involvement of a base station105.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., via an Si or otherinterface). Base stations 105 may communicate with one another overbackhaul links 134 (e.g., via an X2 or other interface) either directly(e.g., directly between base stations 105) or indirectly (e.g., via corenetwork 130).

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC), which may include at least one mobilitymanagement entity (MME), at least one serving gateway (S-GW), and atleast one Packet Data Network (PDN) gateway (P-GW). The MME may managenon-access stratum (e.g., control plane) functions such as mobility,authentication, and bearer management for UEs 115 served by basestations 105 associated with the EPC. User IP packets may be transferredthrough the S-GW, which itself may be connected to the P-GW. The P-GWmay provide IP address allocation as well as other functions. The P-GWmay be connected to the network operators IP services. The operators IPservices may include access to the Internet, Intranet(s), an IPMultimedia Subsystem (IMS), or a Packet-Switched (PS) Streaming Service.

At least some of the network devices, such as a base station 105, mayinclude subcomponents such as an access network entity, which may be anexample of an access node controller (ANC). Each access network entitymay communicate with UEs 115 through a number of other access networktransmission entities, which may be referred to as a radio head, a smartradio head, or a transmission/reception point (TRP). In someconfigurations, various functions of each access network entity or basestation 105 may be distributed across various network devices (e.g.,radio heads and access network controllers) or consolidated into asingle network device (e.g., a base station 105).

The wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 MHz to 300 GHz.Generally, the region from 300 MHz to 3 GHz is known as the ultra-highfrequency (UHF) region or decimeter band, since the wavelengths rangefrom approximately one decimeter to one meter in length. UHF waves maybe blocked or redirected by buildings and environmental features.However, the waves may penetrate structures sufficiently for a macrocell to provide service to UEs 115 located indoors. Transmission of UHFwaves may be associated with smaller antennas and shorter range (e.g.,less than 100 km) compared to transmission using the smaller frequenciesand longer waves of the high frequency (HF) or very high frequency (VHF)portion of the spectrum below 300 MHz.

The wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band. The SHF region includes bands such as the5 GHz industrial, scientific, and medical (ISM) bands, which may be usedopportunistically by devices that can tolerate interference from otherusers.

Wireless communications system 100 may also operate in an extremely highfrequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz),also known as the millimeter band. In some examples, wirelesscommunications system 100 may support millimeter wave (mmW)communications between UEs 115 and base stations 105, and EHF antennasof the respective devices may be even smaller and more closely spacedthan UHF antennas. In some cases, this may facilitate use of antennaarrays within a UE 115. However, the propagation of EHF transmissionsmay be subject to even greater atmospheric attenuation and shorter rangethan SHF or UHF transmissions. Techniques disclosed herein may beemployed across transmissions that use one or more different frequencyregions, and designated use of bands across these frequency regions maydiffer by country or regulating body.

In some cases, the wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example, thewireless communications system 100 may employ License Assisted Access(LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technologyin an unlicensed band such as the 5 GHz ISM band. When operating inunlicensed radio frequency spectrum bands, wireless devices such as basestations 105 and UEs 115 may employ listen-before-talk (LBT) proceduresto ensure a frequency channel is clear before transmitting data. In somecases, operations in unlicensed bands may be based on a CA configurationin conjunction with CCs operating in a licensed band (e.g., LAA).Operations in unlicensed spectrum may include downlink transmissions,uplink transmissions, peer-to-peer transmissions, or a combination ofthese. Duplexing in unlicensed spectrum may be based on frequencydivision duplexing (FDD), time division duplexing (TDD), or acombination of both.

In some examples, base station 105 or UE 115 may be equipped withmultiple antennas, which may be used to employ techniques such astransmit diversity, receive diversity, multiple-input multiple-output(MIMO) communications, or beamforming. For example, the wirelesscommunications system 100 may use a transmission scheme between atransmitting device (e.g., a base station 105) and a receiving device(e.g., a UE 115), where the transmitting device is equipped withmultiple antennas and the receiving devices are equipped with one ormore antennas. MIMO communications may employ multipath signalpropagation to increase the spectral efficiency by transmitting orreceiving multiple signals via different spatial layers, which may bereferred to as spatial multiplexing. The multiple signals may, forexample, be transmitted by the transmitting device via differentantennas or different combinations of antennas. Likewise, the multiplesignals may be received by the receiving device via different antennasor different combinations of antennas. Each of the multiple signals maybe referred to as a separate spatial stream, and may carry bitsassociated with the same data stream (e.g., the same codeword) ordifferent data streams. Different spatial layers may be associated withdifferent antenna ports used for channel measurement and reporting. MIMOtechniques include single-user MIMO (SU-MIMO) where multiple spatiallayers are transmitted to the same receiving device, and multiple-userMIMO (MU-MIMO) where multiple spatial layers are transmitted to multipledevices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105 or a UE 115) to shape orsteer an antenna beam (e.g., a transmit beam or receive beam) along aspatial path between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that signals propagating atparticular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying certain amplitude and phase offsets to signals carried via eachof the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

In one example, a base station 105 may use multiple antennas or antennaarrays to conduct beamforming operations for directional communicationswith a UE 115. For instance, some signals (e.g. synchronization signals,reference signals, beam selection signals, or other control signals) maybe transmitted by a base station 105 multiple times in differentdirections, which may include a signal being transmitted according todifferent beamforming weight sets associated with different directionsof transmission. Transmissions in different beam directions may be usedto identify (e.g., by the base station 105 or a receiving device, suchas a UE 115) a beam direction for subsequent transmission and/orreception by the base station 105. Some signals, such as data signalsassociated with a particular receiving device, may be transmitted by abase station 105 in a single beam direction (e.g., a directionassociated with the receiving device, such as a UE 115). In someexamples, the beam direction associated with transmissions along asingle beam direction may be determined based at least in in part on asignal that was transmitted in different beam directions. For example, aUE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions, and the UE 115 may report to thebase station 105 an indication of the signal it received with a highestsignal quality, or an otherwise acceptable signal quality. Althoughthese techniques are described with reference to signals transmitted inone or more directions by a base station 105, a UE 115 may employsimilar techniques for transmitting signals multiple times in differentdirections (e.g., for identifying a beam direction for subsequenttransmission or reception by the UE 115), or transmitting a signal in asingle direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE 115, which may be an example of a mmWreceiving device) may try multiple receive beams when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets applied to signals receivedat a plurality of antenna elements of an antenna array, or by processingreceived signals according to different receive beamforming weight setsapplied to signals received at a plurality of antenna elements of anantenna array, any of which may be referred to as “listening” accordingto different receive beams or receive directions. In some examples areceiving device may use a single receive beam to receive along a singlebeam direction (e.g., when receiving a data signal). The single receivebeam may be aligned in a beam direction determined based on listeningaccording to different receive beam directions (e.g., a beam directiondetermined to have a highest signal strength, highest signal-to-noiseratio, or otherwise acceptable signal quality based at least in part onlistening according to multiple beam directions).

In some cases, the antennas of a base station 105 or UE 115 may belocated within one or more antenna arrays, which may support MIMOoperations, or transmit or receive beamforming. For example, one or morebase station antennas or antenna arrays may be co-located at an antennaassembly, such as an antenna tower. In some cases, antennas or antennaarrays associated with a base station 105 may be located in diversegeographic locations. A base station 105 may have an antenna array witha number of rows and columns of antenna ports that the base station 105may use to support beamforming of communications with a UE 115.Likewise, a UE 115 may have one or more antenna arrays that may supportvarious MIMO or beamforming operations.

In some cases, the wireless communications system 100 may be apacket-based network that operate according to a layered protocol stack.In the user plane, communications at the bearer or Packet DataConvergence Protocol (PDCP) layer may be IP-based. A Radio Link Control(RLC) layer may in some cases perform packet segmentation and reassemblyto communicate over logical channels. A Medium Access Control (MAC)layer may perform priority handling and multiplexing of logical channelsinto transport channels. The MAC layer may also use hybrid automaticrepeat request (HARQ) to provide retransmission at the MAC layer toimprove link efficiency. In the control plane, the Radio ResourceControl (RRC) protocol layer may provide establishment, configuration,and maintenance of an RRC connection between a UE 115 and a base station105 or core network 130 supporting radio bearers for user plane data. Atthe Physical (PHY) layer, transport channels may be mapped to physicalchannels.

In some cases, UEs 115 and base stations 105 may support retransmissionsof data to increase the likelihood that data is received successfully.HARQ feedback is one technique of increasing the likelihood that data isreceived correctly over a communication link 125. HARQ may include acombination of error detection (e.g., using a cyclic redundancy check(CRC)), forward error correction (FEC), and retransmission (e.g.,automatic repeat request (ARQ)). HARQ may improve throughput at the MAClayer in poor radio conditions (e.g., signal-to-noise conditions). Insome cases, a wireless device may support same-slot HARQ feedback, wherethe device may provide HARQ feedback in a specific slot for datareceived in a previous symbol in the slot. In other cases, the devicemay provide HARQ feedback in a subsequent slot, or according to someother time interval.

Time intervals in LTE or NR may be expressed in multiples of a basictime unit, which may, for example, refer to a sampling period ofT_(s)=1/30,720,000 seconds. Time intervals of a communications resourcemay be organized according to radio frames each having a duration of 10milliseconds (ms), where the frame period may be expressed asT_(f)=307,200 T_(s). The radio frames may be identified by a systemframe number (SFN) ranging from 0 to 1023. Each frame may include 10subframes numbered from 0 to 9, and each subframe may have a duration of1 ms. A subframe may be further divided into 2 slots each having aduration of 0.5 ms, and each slot may contain 6 or 7 modulation symbolperiods (e.g., depending on the length of the cyclic prefix prepended toeach symbol period). Excluding the cyclic prefix, each symbol period maycontain 2048 sampling periods. In some cases a subframe may be thesmallest scheduling unit of the wireless communications system 100, andmay be referred to as a transmission time interval (TTI). In othercases, a smallest scheduling unit of the wireless communications system100 may be shorter than a subframe or may be dynamically selected (e.g.,in bursts of shortened TTIs (sTTIs) or in selected component carriersusing sTTIs).

In some wireless communications systems, a slot may further be dividedinto multiple mini-slots containing one or more symbols. In someinstances, a symbol of a mini-slot or a mini-slot may be the smallestunit of scheduling. Each symbol may vary in duration depending on thesubcarrier spacing or frequency band of operation, for example. Further,some wireless communications systems may implement slot aggregation inwhich multiple slots or mini-slots are aggregated together and used forcommunication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resourceshaving a defined physical layer structure for supporting communicationsover a communication link 125. For example, a carrier of a communicationlink 125 may include a portion of a radio frequency spectrum band thatis operated according to physical layer channels for a given radioaccess technology. Each physical layer channel may carry user data,control information, or other signaling. A carrier may be associatedwith a pre-defined frequency channel (e.g., an E-UTRA absolute radiofrequency channel number (EARFCN)), and may be positioned according to achannel raster for discovery by UEs 115. Carriers may be downlink oruplink (e.g., in an FDD mode), or be configured to carry downlink anduplink communications (e.g., in a TDD mode). In some examples, signalwaveforms transmitted over a carrier may be made up of multiplesub-carriers (e.g., using multi-carrier modulation (MCM) techniques suchas OFDM or DFT-s-OFDM).

The organizational structure of the carriers may be different fordifferent radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR,etc.). For example, communications over a carrier may be organizedaccording to TTIs or slots, each of which may include user data as wellas control information or signaling to support decoding the user data. Acarrier may also include dedicated acquisition signaling (e.g.,synchronization signals or system information, etc.) and controlsignaling that coordinates operation for the carrier. In some examples(e.g., in a carrier aggregation configuration), a carrier may also haveacquisition signaling or control signaling that coordinates operationsfor other carriers.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using time divisionmultiplexing (TDM) techniques, frequency division multiplexing (FDM)techniques, or hybrid TDM-FDM techniques. In some examples, controlinformation transmitted in a physical control channel may be distributedbetween different control regions in a cascaded manner (e.g., between acommon control region or common search space set and one or moreUE-specific control regions or UE-specific search space sets).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of predetermined bandwidths for carriers of a particularradio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). Insome examples, each served UE 115 may be configured for operating overportions or all of the carrier bandwidth. In other examples, some UEs115 may be configured for operation using a narrowband protocol typethat is associated with a predefined portion or range (e.g., set ofsubcarriers or RBs) within a carrier (e.g., “in-band” deployment of anarrowband protocol type).

In a system employing MCM techniques, a resource element may consist ofone symbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme).Thus, the more resource elements that a UE 115 receives and the higherthe order of the modulation scheme, the higher the data rate may be forthe UE 115. In MIMO systems, a wireless communications resource mayrefer to a combination of a radio frequency spectrum resource, a timeresource, and a spatial resource (e.g., spatial layers), and the use ofmultiple spatial layers may further increase the data rate forcommunications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations105 or UEs 115) may have a hardware configuration that supportscommunications over a particular carrier bandwidth, or may beconfigurable to support communications over one of a set of carrierbandwidths. In some examples, the wireless communications system 100 mayinclude base stations 105 and/or UEs that can support simultaneouscommunications via carriers associated with more than one differentcarrier bandwidth.

The wireless communications system 100 may support communication with aUE 115 on multiple cells or carriers, a feature which may be referred toas carrier aggregation (CA) or multi-carrier operation. A UE 115 may beconfigured with multiple downlink CCs and one or more uplink CCsaccording to a carrier aggregation configuration. Carrier aggregationmay be used with both FDD and TDD component carriers. In some cases, thewireless communications system 100 may utilize enhanced componentcarriers (eCCs). An eCC may be characterized by one or more featuresincluding wider carrier or frequency channel bandwidth, shorter symbolduration, shorter TTI duration, or modified control channelconfiguration. In some cases, an eCC may be associated with a carrieraggregation configuration or a dual connectivity configuration (e.g.,when multiple serving cells have a suboptimal or non-ideal backhaullink). An eCC may also be configured for use in unlicensed spectrum orshared spectrum (e.g., where more than one operator is allowed to usethe spectrum). An eCC characterized by wide carrier bandwidth mayinclude one or more segments that may be utilized by UEs 115 that arenot capable of monitoring the whole carrier bandwidth or are otherwiseconfigured to use a limited carrier bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than otherCCs, which may include use of a reduced symbol duration as compared withsymbol durations of the other CCs. A shorter symbol duration may beassociated with increased spacing between adjacent subcarriers. Adevice, such as a UE 115 or base station 105, utilizing eCCs maytransmit wideband signals (e.g., according to frequency channel orcarrier bandwidths of 20, 40, 60, 80 MHz, etc.) at reduced symboldurations (e.g., 16.67 microseconds). A TTI in eCC may consist of one ormultiple symbol periods. In some cases, the TTI duration (that is, thenumber of symbol periods in a TTI) may be variable.

Wireless communications systems such as an NR system may utilize anycombination of licensed, shared, and unlicensed spectrum bands, amongothers. The flexibility of eCC symbol duration and subcarrier spacingmay allow for the use of eCC across multiple spectrums. In someexamples, NR shared spectrum may increase spectrum utilization andspectral efficiency, specifically through dynamic vertical (e.g., acrossfrequency) and horizontal (e.g., across time) sharing of resources.

A base station 105 may identify frequency resources for a PDSCH to betransmitted to a UE 115 in a first TTI. In some cases, the base station105 may transmit, to the UE 115, configuration information for a controlchannel search space set in a second TTI. The second TTI may bepreceding the first TTI. The configuration information may include anindication of an absence of a PDCCH transmission to be sent in thecontrol channel search space set to indicate the identified frequencyresources for the PDSCH, and a set of frequency resources for thecontrol channel search space set. In some cases, the base station 105may transmit the configuration information for the control channelsearch space set using RRC signaling. The configuration information mayinclude a coreset configuration, or the identified time resources,frequency resources, or both, corresponding to resources of the coresetconfiguration, or both. The UE 115 may receive the configurationinformation for the control channel search space set in the first TTI,and identify frequency resources allocated for the PDSCH in the secondTTI based at least in part on the set of time and/or frequency resourcesfor the control channel search space set in the first TTI and theindication of the absence of a PDCCH transmission to be sent in thecontrol channel search space set. The UE 115 may refrain from performingblind decoding in the control channel search space set based onreceiving the indication of the absence of the PDCCH transmission (e.g.,an indication that the number of PDCCH candidates is zero). In somecases, the base station 105 may transmit in a field of a DCI, atransmission configuration indication (TCI) state. The TCI stateincluding a spatial quasi-collocation (QCL) parameter for a beamindication, which the UE 115 may receive.

The base station 105 may transmit (and the UE 115 may receive) a PDSCHtransmission in the first TTI using the identified frequency resourcesfor the PDSCH, to the UE 115. In some cases, the base station 105 maytransmit (and the UE 115 may receive) the PDSCH transmission in thefirst TTI using a beam corresponding to the identified frequencyresources based at least in part on a scheduling offset of the PDSCHtransmission being greater than, or greater than or equal to, athreshold value. Alternatively, the base station 105 may transmit (andthe UE 115 may receive) the PDSCH transmission in the first TTI using afirst beam based at least in part on a scheduling offset of the PDSCHtransmission being less than, or less than or equal to, a thresholdvalue. The first beam being different from a second beam correspondingto the identified frequency resources.

FIG. 2 illustrates an example of a wireless communications system 200that supports virtual search space sets for beam indication inaccordance with various aspects of the present disclosure. In someexamples, the wireless communications system 200 may implement aspectsof the wireless communications system 100. The wireless communicationssystem 200 may include a base station 205 and a UE 215, which may beexamples of the corresponding devices described with reference to FIG. 1. The wireless communications system 200 may also operate according to aradio access technology (RAT) such as a fifth generation (5G) new radio(NR) RAT, although techniques described herein may be applied to any RATand to systems that may concurrently use two or more different RATs thatsupport beamformed transmissions. Some examples of the wirelesscommunications system 200 may support one or more virtual search spacesets to reduce overhead and decrease unnecessary blind decoding of aphysical channel (e.g., a PDCCH).

The base station 205 may perform a RRC procedure (e.g., cell acquisitionprocedure, random access procedure, RRC connection procedure, RRCconfiguration procedure) with the UE 215. The base station 205 may beconfigured with multiple antennas, which may be used for directional orbeamformed transmissions (e.g., beamformed communication beams 220-athrough 220-g). In some examples, the RRC procedure may include a beamsweep procedure. As illustrated in FIG. 2 , the base station 205 maytransmit a number of beamformed communication beams 220-a through 220-gin different directions within a coverage area.

As part of the RRC procedure, the base station 205 and the UE 215 maysynchronize before the base station 205 schedules and allocatesresources (e.g., time and frequency resources) for the UE 215. The basestation 205 may transmit one or more synchronization signals, associatedwith a carrier bandwidth for synchronization. A synchronization signalmay include, for example, a primary synchronization signal and asecondary synchronization signal. To determine a suitable communicationbeam 220 for communication, the base station 205 may transmit one ormore synchronization signals in one or more transmissions 225 accordingto a beam sweep pattern. In some cases, the UE 215 may betime-synchronized with the base station 205, and may be capable ofreceiving one or more transmissions 225 during a slot, a TTI, ashortened-TTI (s-TTI), a subframe or a frame, etc.

The base station 205 may schedule and allocate resources to the UE 215for a transmission 225 via a beamformed transmission (e.g., beamformedcommunication beam 220-a). For example, the base station 205 mayschedule and allocate resources for a downlink transmission of controlinformation. The base station 205 may, in some cases, configure acoreset and search space set for transmission of control information(e.g., DCI) to the UE 215 on a PDCCH. A search space set may refer to acoreset, which may be identified based on an identifier of the coreset(e.g., coreset-ID). A search space set may refer to any resources (e.g.,time and frequency resources such as groups of resource elements,resource element groups, etc.) used for transmitting control informationwithin a given slot (e.g., a TTI, an s-TTI).

The slot may be part of a resource grid that may correspond to a systembandwidth that the base station 205 may allocate to the UE 215, In somecases, the resource grid may continue indefinitely in time. Informationmay be organized as a function of frequency as well as time using theresource grid. A resource element in a resource grid may span one symbolby one sub-carrier. Each resource element may carry two, four, or sixphysical channel bits. Resource elements may be grouped into resourceblocks (RBs), each of which may span a certain frequency range, forexample of 180 kHz (e.g., 12 sub-carriers). The base station 205 mayallocate RBs to the UE 215 by allocating the symbols and sub-carrierswithin each slot in units of the corresponding RBs to the UE 215. Eachslot may span a number of symbol periods (e.g., 14 modulation symbolperiods) (e.g., OFDM symbols) and a number of sub-carriers within abandwidth.

A coreset may span multiple RBs in a frequency domain, and may span anumber of modulation symbol periods in a time domain. The coreset may bedivided into a number of CCEs, and may support a number of differentaggregation levels for transmission of control information. Eachaggregation level may correspond to the number of CCEs allocated for aPDCCH candidate. For example, an aggregation level of four may indicatethat the base station 205 transmits control information for thataggregation level in multiples of four CCEs of a coreset. This controlinformation contained within a four CCE-length segment may be referredto as a search candidate or a PDCCH decoding candidate. In some cases,multiple coresets may be configured for a slot. The base station 205 maytransmit a DCI within a search space set in search candidates (e.g.,PDCCH decoding candidates) for different aggregation levels. The UE 215may monitor the search space set for the search candidates (e.g., PDCCHdecoding candidates), and may perform blind decoding for the PDCCHcandidates, during which the UE 215 may carry out multiple decodeattempts in the search space sets until detecting the DCI. In someexamples, the DCI carried on the PDCCH may include a schedule andallocation of resources (e.g., time and frequency resources) for a PDSCHtransmission.

The UE 215 may be preconfigured with search space configurationinformation. In some cases, the base station 205 may transmitconfiguration information associated with a search space set to the UE215. The configuration information may include an RRC parameterindicated to the UE 215 via higher layer signaling (e.g., RRCsignaling). The RRC parameter may include an indication of whether a TCIis present in the DCI. In some examples, the base station 205 mayconfigure multiple TCI states for the UE 215 for a QCL indication (e.g.,including spatial QCL parameter for beam indication). For example, if anRRC parameter TCI-PresentInDCI is set as ‘enabled’ for the coresetscheduling a PDSCH transmission, the UE 215 may assume that a TCI fieldis always present in the DCI of the PDCCH transmitted on the coreset.Alternatively, if the parameter TCI-PresentInDCI is set as ‘disabled’for the coreset scheduling the PDSCH, the UE 215 may assume that the TCIstate for the PDSCH is identical with the TCI state applied for thecoreset used for the PDCCH transmission.

In such cases, if the parameter TCI-PresentinDCI is set as ‘enabled’,the UE 215 may use the TCI-States according to the value of the TCIfield detected in the PDCCH with DCI for selecting a directional orbeamformed beam (e.g., beamformed communication beams 220-a through220-g) for PDSCH reception. In some examples, for both cases whereTCI-PresentInDCI is ‘enabled’ and TCI-PresentInDCI is ‘disabled,’ if ascheduling offset k₀ is less than a threshold, the UE 215 may use adirectional or beamformed beam based on the TCI state used for PDCCH QCLindication of the lowest coreset-ID in a latest slot in which one ormore coresets are configured for the UE 215. Alternatively, the UE 215may use a directional or beamformed beam for PDSCH given by the TCIstate indicated in the DCI, if the offset k₀ between the reception ofthe DCI and the corresponding PDSCH is equal to or greater than thethreshold. However, for some PDSCH transmissions without a schedulingPDCCH (e.g., in semi-persistent scheduling), a default directional orbeamformed beam from a recent coreset may be invalid (e.g., when asearch space set monitoring periodicity is very large (a periodicitygreater than a configured threshold value)). However, having the basestation 205 configure multiple search space sets having a smallperiodicity (a periodicity lesser than a configured threshold value) fordefault beam indication may unnecessarily increase the overhead of PDCCHblind decoding for the UE 215.

The base station 205 may configure a virtual search space set for the UE215. The wireless communications system 200 may support a zero number ofPDCCH candidates at least for virtual search space set configuration.The virtual search space set may be one type of search space set definedand used for PDSCH beam indication. In some cases, the wirelesscommunication system 200 may configure separate sets of search spacesets. For example, a first set may include a number of virtual searchspace sets and a second set may include a number of normal search spacesets. The number of normal search space sets per bandwidth part (BWP)may be limited to restrict UE's blind decoding overhead. However, avirtual search space set configured by the base station 205 may notincrease an overhead of blind decoding for the UE 215, and the number ofvirtual search space sets may be much larger than the number of normalsearch space sets.

A virtual search space set, as described herein, may refer to a searchspace set that is absent of PDCCH candidates (e.g., has been indicatedas not including any PDCCH candidates). As such, if the UE 215 isconfigured with a virtual search space set, the UE 215 may notanticipate a PDCCH transmission within the search space set and thus mayrefrain from performing blind decoding in the virtual search space set.Since there is no actual PDCCH transmission, the time/frequencyresources associated with the virtual search space set may be reused byother transmissions, such as PDSCH and/or reference signals. In somecases, the base station 205 may reuse an existing search space setconfiguration to configure the virtual search space set. For example,the base station 205 may reconfigure an existing search space setconfiguration by setting a number of PDCCH candidates (nrofCandidates)to zero for some or all aggregation levels. In addition, the basestation 205 may not use some existing search space set configurationparameters for configuring a virtual search space set.

The base station 205 may configure or reconfigure the RRC parameter toindicate a virtual search space set configuration. For example, the basestation 205 may use the TCI state for PDCCH QCL indication of alowest-indexed coreset among a number of coresets including a searchspace set (e.g., either virtual or normal) configured for the UE 215with a latest modulation symbol period (e.g., OFDM symbol). As such,rather than applying a TCI state for a coreset with a latest slot, theUE 215 may use the TCI state for a coreset with a latest OFDM symbol. Insome cases, a directional or beamformed beam for PDSCH may use a defaultTCI state when the scheduling offset k₀ (e.g., in units of TTIs orslots) is less than a threshold offset (e.g., a threshold number of TTIsor slots) for examples where TCI-PresentInDCI is ‘enabled’ and whereTCI-PresentInDCI is ‘disabled.’ In some cases, the base station 205 mayschedule the PDSCH according to semi-persistent scheduling.

FIG. 3 illustrates an example of a configuration 300 that supports avirtual search space set for beam indication in accordance with variousaspects of the present disclosure. In some examples, the configuration300 may implement aspects of the wireless communications system 100 and200. In some examples, the configuration 300 may support semi-persistentscheduling with beam indication.

The configuration 300 may illustrate portions of a resource grid. Withreference to FIG. 2 , the resource grid may correspond to a systembandwidth 305 that the base station 205 may allocate to the UE 215, andthe resource grid may continue indefinitely in time. Information may beorganized as a function of frequency as well as time using the resourcegrid. A resource element may span one symbol by one sub-carrier. Eachresource element may carry two, four, or six physical channel bitsdepending on the modulation coding scheme (MCS) (e.g., quadrature phaseshift keying (QPSK), 16-quadrature amplitude modulation (QAM), 64-QAM,or the like). The base station 205 may group resource elements into RBs,each of which may span a certain frequency range, for example 180 kHz(e.g., 12 sub-carriers). In addition, the base station 205 may allocateRBs to the UE 215 by allocating the symbols and sub-carriers within eachslot 310 (e.g., slot 310-a through slot 310-g) in units of RBs to the UE215. Each slot 310-a through 310-g may span 14 modulation symbol periodsand a number of subcarriers within the system bandwidth 305.

Some examples of wireless communications systems (e.g., fourthgeneration (4G) long-term evolution (LTE)), may RRC configureperiodicity of semi-persistent scheduled PDSCH. In some cases, the basestation 205 may also transmit PDCCH with semi-persistent schedulingcell-radio network temporary identifier (SPS-C-RNTI) to allocateresources and trigger semi-persistent scheduled PDSCH transmissions.

The UE 215 may receive a semi-persistent scheduled PDSCH 325 in slot310-c. The first semi-persistent scheduled PDSCH 325 in slot 310-c mayfollow rules and procedures similar to normal PDSCH. A secondsemi-persistent scheduled PDSCH 325 in slot 310-e and so forth may use adefault beam, as long as there is no PDCCH overriding the resources ofsemi-persistent scheduled PDSCH 325. If there is a PDCCH overriding theresources, the same rules and procedure as normal PDSCH apply withrespect to the PDCCH. The rules may be based on a TCI-PresentInDCIindication, scheduling offset k₀, and a threshold value.

A coreset 315 in slot 310-a may carry a PDCCH 320 with SPS-C-RNTI. ThePDCCH 320 with SPS-C-RNTI may carry a DCI providing schedulinginformation for a corresponding semi-persistent scheduled PDSCH 325. TheDCI may include a field indicating a TCI state when TCI-PresentInDCI is‘enabled.’ The TCI state may include a spatial QCL parameter for a beamindication. In some cases, if a scheduling offset k₀ is greater than orequal to a threshold, the TCI state included in the DCI of the PDCCH 320in slot 310-a may indicate a beam indication for a semi-persistentscheduled PDSCH 325 in slot 310-c. When TCI-PresentInDCI is ‘disabled,’and if a scheduling offset k₀ is greater than or equal to a threshold,the same TCI state applied for the coreset 315 in slot 310-a may beassumed for the TCI state for the semi-persistent scheduled PDSCH 325 inslot 310-c.

Two coresets 315 may be present in the example of slot 310-b, which isthe latest slot before PDSCH 325 in slot 310-c where one or morecoresets are configured for the UE 215. In this case, the UE 215 mayselect a beam indication for a semi-persistent scheduled PDSCH 325 inslot 310-c based on an indication of a TCI state applied for a coresetclosest to the PDSCH 325 (i.e., indicated by TCI state of coreset withthe latest/most recent OFDM symbol) (in this case, the coreset in themiddle portion of the slot 310-b), and based on if the scheduling offsetis lesser than the threshold.

In slot 310-d, which is the latest slot before semi-persistent scheduledPDSCH 325 in slot 310-e in which one or more coresets are configured forthe UE 215, a coreset 315 configured for the UE 215 may not include anyPDCCH, and may indicate the beam for the PDSCH 325 in slot 310-e basedon an indication of a TCI state applied for the coreset. The basestation 205 may configure a virtual search space set for the UE 215 inwhich no PDCCH 320 are configured for sending. The base station 205 maygenerate configuration information that may be for a control channelsearch space set in slot 310-f. The base station 205 may transmit theconfiguration information to the UE 215 via RRC signaling. Theconfiguration information may include an RRC parameter that may indicatean absence or lack of a PDCCH transmission to be sent in the controlchannel search space set (e.g., by indicating that a number of candidatePDCCHs 320 is 0). In some cases, a configured coreset 330 may be part ofslot 310-f. The configured coreset 330 may contain a virtual searchspace set. The virtual search space set may indicate a beam indicationfor receiving a semi-persistent scheduled PDSCH 325 during slot 310-gbased on an indication of a TCI state applied for the configured coreset330. Based on receiving the configuration information from the basestation 205, the UE 215 may refrain from performing blind decoding onthe configured coreset 330 because of the indication of the absence orlack of a PDCCH transmission during slot 310-f based on the virtualsearch space configuration. The UE 215 may receive the semi-persistentscheduled PDSCH 325 during slot 310-g using a beam corresponding to thebeam indication related to the virtual search space set. The UE 215 mayalso refrain from performing blind decoding in the virtual search spaceset of slot 310-f.

FIG. 4 illustrates an example of a process flow 400 that supportsvirtual search space set for beam indication in accordance with variousaspects of the present disclosure. In some examples, the process flow400 may implement aspects of wireless communications system 100 and 200.Base station 405 and UE 415 may be examples of the corresponding devicesdescribed with reference to FIGS. 1 and 2 .

In the following description of the process flow 400, the operationsbetween the base station 405 and the UE 415 may be transmitted in adifferent order than the exemplary order shown, or the operationsperformed by the base station 405 and the UE 415 may be performed indifferent orders or at different times. Certain operations may also beleft out of the process flow 400, or other operations may be added tothe process flow 400.

In some examples, the process flow may commence with the base station405 establishing a connection with the UE 415 (e.g., performing a cellacquisition procedure, a random access procedure, an RRC connectionprocedure, an RRC configuration procedure, etc.).

At 420, the base station 405 may identify resources to be used totransmit using a PDSCH to UE 415. For example, the base station 405 mayidentify frequency and time resources for a PDSCH to be transmitted tothe UE in a first TTI. The base station 405 may identify the resourcesbased on a semi-persistent scheduling for the UE 415. UE 415 may havebeen previously provided the configuration information for thesemi-persistent scheduling by base station 405, for example, as part ofcontrol information transmitted over a PDCCH.

In some examples, the base station 405 may communicate with the UE 415,and may send control transmissions, such as DCI, via a PDCCH. In someexamples, control information, such as DCI, may be included in acoreset. The DCI may schedule and allocate resources for the PDSCH. TheUE 415 may be configured to monitor a PDCCH within a search space set,which may include multiple search candidates. In some cases, searchcandidates may be control channel candidates or PDCCH candidates. Infurther cases, each search space set may include multiple CCEs, and mayinclude one or more search candidates, each of which may include one ormore CCEs. The UE 415 may be configured to monitor one or more searchcandidates in the search space set, and may blindly decode the one ormore CCEs of the search candidate to receive control information.

However, for some PDSCH without a scheduling PDCCH (e.g., in the case ofsemi-persistent scheduling of the PDSCH), a default directional orbeamformed beam from a recent coreset may be outdated (e.g., when asearch space set monitoring periodicity is very large, and a UE 415 mayhave moved or the channel conditions for the beam may have degraded overtime). However, in cases where the base station 405 configures multiplesearch space sets having a small periodicity for the default beamindication may unnecessarily increase the overhead of PDCCH blinddecoding for the UE 415. The base station 405 may configure a virtualsearch space set for the UE 415, in which no PDCCH are configured to besent. As such the UE 415 may refrain from blind decoding in the virtualsearch space set. The base station 405 may configure or reconfigure anRRC parameter to indicate a virtual search space configuration to the UE415.

At 425, the base station 405 may generate configuration information. Insome cases, the configuration information may include a coresetconfiguration, the identified frequency resources corresponding toresources of the coreset configuration. For example, the base station405 may generate configuration information that may be for a controlchannel search space set in a second TTI. The second TTI may precede thefirst TTI. The configuration information may include an indication of anabsence or lack of a PDCCH transmission to be sent in the controlchannel search space set (e.g., by indicating that a number of PDCCH is0) to indicate the identified frequency resources for the PDSCH, and aset of frequency resources for the control channel search space set. Insome cases, the control channel search space set associated with thecoreset contains a zero number of PDCCH candidates.

At 430, the base station 405 may transmit the configuration informationto the UE 415. In some cases, the base station 405 may transmitconfiguration information for a control channel search space set usingRRC signaling.

At 435, the UE 415 may receive the configuration information from thebase station 405. At 440, the UE 415 may identify resources allocatedfor the PDSCH. For example, the UE 415 may identify frequency and timeresources allocated for the PDSCH in the second TTI based on the set offrequency resources for the control channel search space set in thefirst TTI and the indication of the absence of a PDCCH transmission inthe control channel search space set. In some cases, the UE 415 mayrefrain from performing blind decoding in the control channel searchspace set based on receiving the indication of the absence of the PDCCHtransmission.

At 445, the base station 405 may transmit PDSCH to the UE 415. The UE415 may receive the PDSCH transmission in the second TTI using theidentified frequency resources. In some examples, the UE 415 may receivethe PDSCH transmission in the second TTI using a beam corresponding tothe identified frequency resources based at least in part on ascheduling offset of the PDSCH transmission being greater than or equalto a threshold value. Alternatively, the UE 415 may receive the PDSCHtransmission in the second TTI using a first beam based on a schedulingoffset of the PDSCH transmission being less than or equal to a thresholdvalue. The first beam may be different from a second beam correspondingto the identified frequency resources.

FIG. 5 shows a block diagram 500 of a wireless device 505 that supportsvirtual search space sets for beam indication in accordance with aspectsof the present disclosure. Wireless device 505 may be an example ofaspects of a UE 115 as described herein. Wireless device 505 may includereceiver 510, UE communications manager 515, and transmitter 520.Wireless device 505 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 510 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to virtualsearch space sets for beam indication, etc.). The receiver may passinformation on to other components of the device. The receiver 510 maybe an example of aspects of the transceiver 835 described with referenceto FIG. 8 . The receiver 510 may utilize a single antenna or a set ofantennas.

UE communications manager 515 may be an example of aspects of the UEcommunications manager 815 described with reference to FIG. 8 . UEcommunications manager 515 and/or at least some of its varioussub-components may be implemented in hardware, software executed by aprocessor, firmware, or any combination thereof. If implemented insoftware executed by a processor, the functions of the UE communicationsmanager 515 and/or at least some of its various sub-components may beexecuted by a general-purpose processor, a digital signal processor(DSP), an application-specific integrated circuit (ASIC), anfield-programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described in thepresent disclosure.

The UE communications manager 515 and/or at least some of its varioussub-components may be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations by one or more physical devices. In someexamples, UE communications manager 515 and/or at least some of itsvarious sub-components may be a separate and distinct component inaccordance with various aspects of the present disclosure. In otherexamples, UE communications manager 515 and/or at least some of itsvarious sub-components may be combined with one or more other hardwarecomponents, including but not limited to an I/O component, atransceiver, a network server, another computing device, one or moreother components described in the present disclosure, or a combinationthereof in accordance with various aspects of the present disclosure.

UE communications manager 515 may receive configuration information fora control channel search space set in a first TTI, the receivedconfiguration information including an indication of an absence of aPDCCH transmission in the control channel search space set, and a set oftime and frequency resources for the control channel search space set,identify time and frequency resources allocated for a PDSCH in a secondTTI based on the set of time and frequency resources for the controlchannel search space set in the first TTI and the indication of theabsence of a PDCCH transmission the control channel search space set,and receive a PDSCH transmission in the second TTI using the identifiedtime and frequency resources.

Transmitter 520 may transmit signals generated by other components ofthe device. In some examples, the transmitter 520 may be collocated witha receiver 510 in a transceiver module. For example, the transmitter 520may be an example of aspects of the transceiver 835 described withreference to FIG. 8 . The transmitter 520 may utilize a single antennaor a set of antennas.

FIG. 6 shows a block diagram 600 of a wireless device 605 that supportsvirtual search space sets for beam indication in accordance with aspectsof the present disclosure. Wireless device 605 may be an example ofaspects of a wireless device 505 or a UE 115 as described with referenceto FIG. 5 . Wireless device 605 may include receiver 610, UEcommunications manager 615, and transmitter 620. Wireless device 605 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

Receiver 610 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to virtualsearch space sets for beam indication, etc.). Information may be passedon to other components of the device. The receiver 610 may be an exampleof aspects of the transceiver 835 described with reference to FIG. 8 .The receiver 610 may utilize a single antenna or a set of antennas.

UE communications manager 615 may be an example of aspects of the UEcommunications manager 815 described with reference to FIG. 8 . UEcommunications manager 615 may also include configuration component 625,resource component 630, and physical channel component 635.

Configuration component 625 may receive configuration information for acontrol channel search space set in a first TTI. The receivedconfiguration information including an indication of an absence of aPDCCH transmission in the control channel search space set, and a set offrequency resources for the control channel search space set. In somecases, the configuration information for the control channel searchspace set is received in radio resource control signaling. In somecases, the configuration information includes a coreset configurationfrom the base station, a TCI state, and the time and frequency resourcescorresponding to resources of the coreset configuration. In some cases,the control channel search space set associated with the coresetcontains a zero number of PDCCH candidates.

Resource component 630 may identify time and frequency resourcesallocated for a PDSCH in a second TTI based on the set of time andfrequency resources for the control channel search space set in thefirst TTI and the indication of the absence of a PDCCH transmission thecontrol channel search space set.

Physical channel component 635 may receive a first TCI state in a fieldof a DCI, and may receive a PDSCH transmission in the identified timeand frequency resources. Physical channel component 635 may receive thePDSCH transmission in the identified time and frequency resources usinga first beam associated with the received TCI state. The identified timeand frequency resources may be based on a scheduling offset of the PDSCHtransmission being greater than or equal to a threshold value. In someother cases, physical channel component 635 may receive the PDSCHtransmission in the identified time and frequency resources using afirst beam associated with a second TCI state based on a schedulingoffset of the PDSCH transmission being less than or equal to a thresholdvalue, where the first beam may be different from a second beamassociated with the first TCI state, and the second TCI state of acontrol resource set associated with the control channel search spaceset.

Transmitter 620 may transmit signals generated by other components ofthe device. In some examples, the transmitter 620 may be collocated witha receiver 610 in a transceiver module. For example, the transmitter 620may be an example of aspects of the transceiver 835 described withreference to FIG. 8 . The transmitter 620 may utilize a single antennaor a set of antennas.

FIG. 7 shows a block diagram 700 of a UE communications manager 715 thatsupports virtual search space sets for beam indication in accordancewith aspects of the present disclosure. The UE communications manager715 may be an example of aspects of a UE communications manager 515, aUE communications manager 615, or a UE communications manager 815described with reference to FIGS. 5, 6, and 8 . The UE communicationsmanager 715 may include configuration component 720, resource component725, physical channel component 730, decoding component 735, andparameter component 740. Each of these modules may communicate, directlyor indirectly, with one another (e.g., via one or more buses).

Configuration component 720 may receive configuration information for acontrol channel search space set in a first TTI. The receivedconfiguration information including an indication of an absence of aPDCCH transmission in the control channel search space set, and a set oftime and frequency resources for the control channel search space set.In some cases, the configuration information for the control channelsearch space set is received in radio resource control signaling. Insome cases, the configuration information includes a coresetconfiguration from the base station, a TCI state, and the time andfrequency resources corresponding to resources of the coresetconfiguration. In some cases, the control channel search space setassociated with the coreset contains a zero number of PDCCH candidates.

Resource component 725 may identify time and frequency resourcesallocated for a PDSCH in a second TTI based on the set of time andfrequency resources for the control channel search space set in thefirst TTI and the indication of the absence of a PDCCH transmission thecontrol channel search space set.

Physical channel component 730 may receive a first TCI state in a fieldof a DCI, and may receive a PDSCH transmission in the identified timeand frequency resources. Physical channel component 730 may receive thePDSCH transmission in the identified time and frequency resources usinga beam associated with the received TCI state. The identified time andfrequency resources may be based on a scheduling offset of the PDSCHtransmission being greater than or equal to a threshold value. In someother cases, physical channel component 730 may receive the PDSCHtransmission in the identified time and frequency resources using afirst beam associated with a second TCI state based on a schedulingoffset of the PDSCH transmission being less than or equal to a thresholdvalue, where the first beam may be different from a second beamcorresponding to the associated with the first TCI state.

Decoding component 735 may refrain from performing blind decoding in thecontrol channel search space set based on receiving the indication ofthe absence of the PDCCH transmission. Parameter component 740 mayreceive, in a field of a DCI, a TCI state, where the TCI state includesa spatial QCL parameter for a beam indication.

FIG. 8 shows a diagram of a system 800 including a device 805 thatsupports virtual search space sets for beam indication in accordancewith aspects of the present disclosure. Device 805 may be an example ofor include the components of wireless device 505, wireless device 605,or a UE 115 as described above, e.g., with reference to FIGS. 5 and 6 .Device 805 may include components for bi-directional voice and datacommunications including components for transmitting and receivingcommunications, including UE communications manager 815, processor 820,memory 825, software 830, transceiver 835, antenna 840, and I/Ocontroller 845. These components may be in electronic communication viaone or more buses (e.g., bus 810). Device 805 may communicate wirelesslywith one or more base stations 105.

Processor 820 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a central processing unit (CPU), amicrocontroller, an ASIC, an FPGA, a programmable logic device, adiscrete gate or transistor logic component, a discrete hardwarecomponent, or any combination thereof). In some cases, processor 820 maybe configured to operate a memory array using a memory controller. Inother cases, a memory controller may be integrated into processor 820.Processor 820 may be configured to execute computer-readableinstructions stored in a memory to perform various functions (e.g.,functions or tasks supporting virtual search space sets for beamindication).

Memory 825 may include random access memory (RAM) and read only memory(ROM). The memory 825 may store computer-readable, computer-executablesoftware 830 including instructions that, when executed, cause theprocessor to perform various functions described herein. In some cases,the memory 825 may contain, among other things, a basic input/outputsystem (BIOS) which may control basic hardware or software operationsuch as the interaction with peripheral components or devices.

Software 830 may include code to implement aspects of the presentdisclosure, including code to support virtual search space sets for beamindication. Software 830 may be stored in a non-transitorycomputer-readable medium such as system memory or other memory. In somecases, the software 830 may not be directly executable by the processorbut may cause a computer (e.g., when compiled and executed) to performfunctions described herein.

Transceiver 835 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 835 may represent a wireless transceiver and may communicatebi-directionally with another wireless transceiver. The transceiver 835may also include a modem to modulate the packets and provide themodulated packets to the antennas for transmission, and to demodulatepackets received from the antennas. In some cases, the wireless devicemay include a single antenna 840. However, in some cases the device mayhave more than one antenna 840, which may be capable of concurrentlytransmitting or receiving multiple wireless transmissions.

I/O controller 845 may manage input and output signals for device 805.I/O controller 845 may also manage peripherals not integrated intodevice 805. In some cases, I/O controller 845 may represent a physicalconnection or port to an external peripheral. In some cases, I/Ocontroller 845 may utilize an operating system such as iOS®, ANDROID®,MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operatingsystem. In other cases, I/O controller 845 may represent or interactwith a modem, a keyboard, a mouse, a touchscreen, or a similar device.In some cases, I/O controller 845 may be implemented as part of aprocessor. In some cases, a user may interact with device 805 via I/Ocontroller 845 or via hardware components controlled by I/O controller845.

FIG. 9 shows a block diagram 900 of a wireless device 905 that supportsvirtual search space sets for beam indication in accordance with aspectsof the present disclosure. Wireless device 905 may be an example ofaspects of a base station 105 as described herein. Wireless device 905may include receiver 910, base station communications manager 915, andtransmitter 920. Wireless device 905 may also include a processor. Eachof these components may be in communication with one another (e.g., viaone or more buses).

Receiver 910 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to virtualsearch space sets for beam indication, etc.). Information may be passedon to other components of the device. The receiver 910 may be an exampleof aspects of the transceiver 1235 described with reference to FIG. 12 .The receiver 910 may utilize a single antenna or a set of antennas.

Base station communications manager 915 may be an example of aspects ofthe base station communications manager 1215 described with reference toFIG. 12 . Base station communications manager 915 and/or at least someof its various sub-components may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions of thebase station communications manager 915 and/or at least some of itsvarious sub-components may be executed by a general-purpose processor, aDSP, an ASIC, an FPGA or other programmable logic device, discrete gateor transistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described in the presentdisclosure.

The base station communications manager 915 and/or at least some of itsvarious sub-components may be physically located at various positions,including being distributed such that portions of functions areimplemented at different physical locations by one or more physicaldevices. In some examples, base station communications manager 915and/or at least some of its various sub-components may be a separate anddistinct component in accordance with various aspects of the presentdisclosure. In other examples, base station communications manager 915and/or at least some of its various sub-components may be combined withone or more other hardware components, including but not limited to anI/O component, a transceiver, a network server, another computingdevice, one or more other components described in the presentdisclosure, or a combination thereof in accordance with various aspectsof the present disclosure.

Base station communications manager 915 may identify time and frequencyresources for a PDSCH to transmit to a UE in a first TTI, transmit, tothe UE, configuration information for a control channel search space setin a second TTI, the second TTI preceding the first TTI, and theconfiguration information including an indication of an absence of aPDCCH transmission to be sent in the control channel search space set toindicate the identified time and frequency resources for the PDSCH, anda set of time and frequency resources for the control channel searchspace set, and transmit a PDSCH transmission in the first TTI using theidentified time and frequency resources for the PDSCH.

Transmitter 920 may transmit signals generated by other components ofthe device. In some examples, the transmitter 920 may be collocated witha receiver 910 in a transceiver module. For example, the transmitter 920may be an example of aspects of the transceiver 1235 described withreference to FIG. 12 . The transmitter 920 may utilize a single antennaor a set of antennas.

FIG. 10 shows a block diagram 1000 of a wireless device 1005 thatsupports virtual search space sets for beam indication in accordancewith aspects of the present disclosure. Wireless device 1005 may be anexample of aspects of a wireless device 905 or a base station 105 asdescribed with reference to FIG. 9 . Wireless device 1005 may includereceiver 1010, base station communications manager 1015, and transmitter1020. Wireless device 1005 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 1010 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to virtualsearch space sets for beam indication, etc.). Information may be passedon to other components of the device. The receiver 1010 may be anexample of aspects of the transceiver 1235 described with reference toFIG. 12 . The receiver 1010 may utilize a single antenna or a set ofantennas.

Base station communications manager 1015 may be an example of aspects ofthe base station communications manager 1215 described with reference toFIG. 12 . Base station communications manager 1015 may also includeresource component 1025, configuration component 1030, and physicalchannel component 1035. Resource component 1025 may identify time andfrequency resources for a PDSCH to be transmitted to a UE in a firstTTI.

Configuration component 1030 may transmit, to the UE, configurationinformation for a control channel search space set in a second TTI. Thesecond TTI preceding the first TTI, and the configuration informationincluding an indication of an absence of a PDCCH transmission to be sentin the control channel search space set to indicate the identified timeand frequency resources for the PDSCH, and a set of time and frequencyresources for the control channel search space set. Configurationcomponent 1030 may transmit the configuration information for thecontrol channel search space set using radio resource control signaling.In some cases, the configuration information includes a coresetconfiguration, a TCI state, and the time and frequency resourcescorresponding to resources of the coreset configuration. In some cases,the control channel search space set associated with the coresetcontains a zero number of PDCCH candidates.

Physical channel component 1035 may transmit a PDSCH transmission in afirst TCI state in a field of a DCI. Physical channel component 1035 maytransmit the PDSCH transmission in the identified time and frequencyresources using a beam associated with the transmitted TCI state, thetransmission of the PDSCH based on a scheduling offset being greaterthan or equal to a threshold value. In other cases, physical channelcomponent 1035 may transmit the PDSCH transmission in the identifiedtime and frequency resources using a first beam associated with a secondTCI state, and based on a scheduling offset of the PDSCH transmissionbeing less than or equal to a threshold value. The first beam may bedifferent from a second beam associated with the first TCI state, andthe second TCI state of a control resource set associated with thecontrol channel search space set.

Transmitter 1020 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1020 may be collocatedwith a receiver 1010 in a transceiver module. For example, thetransmitter 1020 may be an example of aspects of the transceiver 1235described with reference to FIG. 12 . The transmitter 1020 may utilize asingle antenna or a set of antennas.

FIG. 11 shows a block diagram 1100 of a base station communicationsmanager 1115 that supports virtual search space sets for beam indicationin accordance with aspects of the present disclosure. The base stationcommunications manager 1115 may be an example of aspects of a basestation communications manager 1215 described with reference to FIGS. 9,10, and 12 . The base station communications manager 1115 may includeresource component 1120, configuration component 1125, physical channelcomponent 1130, and parameter component 1135. Each of these modules maycommunicate, directly or indirectly, with one another (e.g., via one ormore buses).

Resource component 1120 may identify time and frequency resources for aPDSCH to transmit to a UE in a first TTI. Configuration component 1125may transmit, to the UE, configuration information for a control channelsearch space set in a second TTI. The second TTI preceding the firstTTI, and the configuration information including an indication of anabsence of a PDCCH transmission to be sent in the control channel searchspace set to indicate the identified time and frequency resources forthe PDSCH, and a set of time and frequency resources for the controlchannel search space set. Configuration component 1125 may transmit theconfiguration information for the control channel search space set usingRRC signaling. In some cases, the configuration information includes acoreset configuration, a TCI state, and the time and frequency resourcescorresponding to resources of the coreset configuration. In some cases,the control channel search space set associated with the coresetcontains a zero number of PDCCH candidates.

Physical channel component 1130 may transmit a PDSCH transmission in afirst TCI state in a field of a DCI. Physical channel component 1130 maytransmit the PDSCH transmission in the identified time and frequencyresources using a beam associated with the transmitted TCI state, thetransmission of the PDSCH based on a scheduling offset being greaterthan or equal to a threshold value. In other cases, physical channelcomponent 1130 may transmit the PDSCH transmission in the identifiedtime and frequency resources using a first beam associated with a secondTCI state, and based on a scheduling offset of the PDSCH transmissionbeing less than or equal to a threshold value. The first beam may bedifferent from a second beam associated with the first TCI state, andthe second TCI state of a control resource set associated with thecontrol channel search space set. Parameter component 1135 may transmit,in a field of a DCI, a TCI state. The TCI state may include a spatialQCL parameter for a beam indication.

FIG. 12 shows a diagram of a system 1200 including a device 1205 thatsupports virtual search space sets for beam indication in accordancewith aspects of the present disclosure. Device 1205 may be an example ofor include the components of base station 105 as described above, e.g.,with reference to FIG. 1 . Device 1205 may include components forbi-directional voice and data communications including components fortransmitting and receiving communications, including base stationcommunications manager 1215, processor 1220, memory 1225, software 1230,transceiver 1235, antenna 1240, network communications manager 1245, andinter-station communications manager 1250. These components may be inelectronic communication via one or more buses (e.g., bus 1210). Device1205 may communicate wirelessly with one or more UEs 115.

Processor 1220 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, processor 1220 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into processor 1220. Processor 1220 may be configured toexecute computer-readable instructions stored in a memory to performvarious functions (e.g., functions or tasks supporting virtual searchspace sets for beam indication).

Memory 1225 may include RAM and ROM. The memory 1225 may storecomputer-readable, computer-executable software 1230 includinginstructions that, when executed, cause the processor to perform variousfunctions described herein. In some cases, the memory 1225 may contain,among other things, a BIOS which may control basic hardware or softwareoperation such as the interaction with peripheral components or devices.

Software 1230 may include code to implement aspects of the presentdisclosure, including code to support virtual search space sets for beamindication. Software 1230 may be stored in a non-transitorycomputer-readable medium such as system memory or other memory. In somecases, the software 1230 may not be directly executable by the processorbut may cause a computer (e.g., when compiled and executed) to performfunctions described herein.

Transceiver 1235 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1235 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1235 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas. In some cases, thewireless device may include a single antenna 1240. However, in somecases the device may have more than one antenna 1240, which may becapable of concurrently transmitting or receiving multiple wirelesstransmissions.

Network communications manager 1245 may manage communications with thecore network (e.g., via one or more wired backhaul links). For example,the network communications manager 1245 may manage the transfer of datacommunications for client devices, such as one or more UEs 115.

Inter-station communications manager 1250 may manage communications withother base station 105, and may include a controller or scheduler forcontrolling communications with UEs 115 in cooperation with other basestations 105. For example, the inter-station communications manager 1250may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, inter-station communications manager1250 may provide an X2 interface within an Long Term Evolution(LTE)/LTE-A wireless communication network technology to providecommunication between base stations 105.

FIG. 13 shows a flowchart illustrating a method 1300 for virtual searchspace sets for beam indication in accordance with aspects of the presentdisclosure. The operations of method 1300 may be implemented by a UE 115or its components as described herein. For example, the operations ofmethod 1300 may be performed by a UE communications manager as describedwith reference to FIGS. 5 through 8 . In some examples, a UE 115 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the UE 115 may perform aspects of the functions described below usingspecial-purpose hardware.

At 1305 the UE 115 may receive configuration information for a controlchannel search space set in a first TTI, the received configurationinformation containing an indication of an absence of a PDCCHtransmission in the control channel search space set, and a set of timeand frequency resources for the control channel search space set. Theoperations of 1305 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1305 may beperformed by a configuration component as described with reference toFIGS. 5 through 8 .

At 1310 the UE 115 may identify time and frequency resources allocatedfor a PDSCH in a second TTI based at least in part on the set of timeand frequency resources for the control channel search space set in thefirst TTI and the indication of the absence of a PDCCH transmission thecontrol channel search space set. The operations of 1310 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1310 may be performed by aresource component as described with reference to FIGS. 5 through 8 .

At 1315 the UE 115 may receive a PDSCH transmission in the second TTIusing the identified time and frequency resources. The operations of1315 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1315 may be performed bya physical channel component as described with reference to FIGS. 5through 8 .

FIG. 14 shows a flowchart illustrating a method 1400 for virtual searchspace sets for beam indication in accordance with aspects of the presentdisclosure. The operations of method 1400 may be implemented by a UE 115or its components as described herein. For example, the operations ofmethod 1400 may be performed by a UE communications manager as describedwith reference to FIGS. 5 through 8 . In some examples, a UE 115 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the UE 115 may perform aspects of the functions described below usingspecial-purpose hardware.

At 1405 the UE 115 may receive configuration information for a controlchannel search space set in a first TTI, the received configurationinformation containing an indication of an absence of a PDCCHtransmission in the control channel search space set, and a set of timeand frequency resources for the control channel search space set. Theoperations of 1405 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1405 may beperformed by a configuration component as described with reference toFIGS. 5 through 8 .

At 1410 the UE 115 may identify time and frequency resources allocatedfor a PDSCH in a second TTI based at least in part on the set of timeand frequency resources for the control channel search space set in thefirst TTI and the indication of the absence of a PDCCH transmission thecontrol channel search space set. The operations of 1410 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1410 may be performed by aresource component as described with reference to FIGS. 5 through 8 .

At 1415 the UE 115 may receive a PDSCH transmission in the second TTIusing the identified time and frequency resources. The operations of1415 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1315 may be performed bya physical channel component as described with reference to FIGS. 5through 8 .

At 1420 the UE 115 may refrain from performing blind decoding in thecontrol channel search space set based at least in part on receiving theindication of the absence of the PDCCH transmission. The operations of1420 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1420 may be performed bya decoding component as described with reference to FIGS. 5 through 8 .

FIG. 15 shows a flowchart illustrating a method 1500 for virtual searchspace sets for beam indication in accordance with aspects of the presentdisclosure. The operations of method 1500 may be implemented by a UE 115or its components as described herein. For example, the operations ofmethod 1500 may be performed by a UE communications manager as describedwith reference to FIGS. 5 through 8 . In some examples, a UE 115 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the UE 115 may perform aspects of the functions described below usingspecial-purpose hardware.

At 1505 the UE 115 may receive configuration information for a controlchannel search space set in a first TTI, the received configurationinformation containing an indication of an absence of a PDCCHtransmission in the control channel search space set, and a set of timeand frequency resources for the control channel search space set. Theoperations of 1505 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1505 may beperformed by a configuration component as described with reference toFIGS. 5 through 8 .

At 1510 the UE 115 may identify time and frequency resources allocatedfor a PDSCH in a second TTI based on the set of time and frequencyresources for the control channel search space set in the first TTI andthe indication of the absence of a PDCCH transmission the controlchannel search space set. The operations of 1510 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1510 may be performed by a resource component asdescribed with reference to FIGS. 5 through 8 .

At 1515 the UE 115 may receive a TCI state in a field of a DCI. Theoperations of 1515 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1515 may beperformed by a physical channel component as described with reference toFIGS. 5 through 8

At 1520 the UE 115 may receive the PDSCH transmission in the identifiedtime and frequency resources using a beam associated with the receivedTCI state based on a scheduling offset of the PDSCH transmission beinggreater than or equal to a threshold value. The operations of 1520 maybe performed according to the methods described herein. In certainexamples, aspects of the operations of 1520 may be performed by aphysical channel component as described with reference to FIGS. 5through 8 .

FIG. 16 shows a flowchart illustrating a method 1600 for virtual searchspace sets for beam indication in accordance with aspects of the presentdisclosure. The operations of method 1600 may be implemented by a UE 115or its components as described herein. For example, the operations ofmethod 1600 may be performed by a UE communications manager as describedwith reference to FIGS. 5 through 8 . In some examples, a UE 115 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the UE 115 may perform aspects of the functions described below usingspecial-purpose hardware.

At 1605 the UE 115 may receive configuration information for a controlchannel search space set in a first TTI, the received configurationinformation containing an indication of an absence of a PDCCHtransmission in the control channel search space set, and a set of timeand frequency resources for the control channel search space set. Theoperations of 1605 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1605 may beperformed by a configuration component as described with reference toFIGS. 5 through 8 .

At 1610 the UE 115 may identify time and frequency resources allocatedfor a PDSCH in a second TTI based on the set of time and frequencyresources for the control channel search space set in the first TTI andthe indication of the absence of a PDCCH transmission the controlchannel search space set. The operations of 1610 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1610 may be performed by a resource component asdescribed with reference to FIGS. 5 through 8 .

At 1615 the UE 115 may receive a TCI state in a field of a DCI. Theoperations of 1615 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1615 may beperformed by a physical channel component as described with reference toFIGS. 5 through 8

At 1620 the UE 115 may receive the PDSCH transmission in the identifiedtime and frequency resources using a first beam associated with a secondTCI state based on a scheduling offset of the PDSCH transmission beingless than or equal to a threshold value, the first beam different from asecond beam associated with the first TCI state, and the second TCIstate of a control resource set associated with the control channelsearch space set. The operations of 1620 may be performed according tothe methods described herein. In certain examples, aspects of theoperations of 1620 may be performed by a physical channel component asdescribed with reference to FIGS. 5 through 8 .

FIG. 17 shows a flowchart illustrating a method 1700 for virtual searchspace sets for beam indication in accordance with aspects of the presentdisclosure. The operations of method 1700 may be implemented by a basestation 105 or its components as described herein. For example, theoperations of method 1700 may be performed by a base stationcommunications manager as described with reference to FIGS. 9 through 12. In some examples, a base station 105 may execute a set of codes tocontrol the functional elements of the device to perform the functionsdescribed below. Additionally or alternatively, the base station 105 mayperform aspects of the functions described below using special-purposehardware.

At 1705 the base station 105 may identify time and frequency resourcesfor a PDSCH to be transmitted to a UE in a first TTI. The operations of1605 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1605 may be performed bya resource component as described with reference to FIGS. 9 through 12 .

At 1710 the base station 105 may transmit, to the UE, configurationinformation for a control channel search space set in a second TTI, thesecond TTI preceding the first TTI, and the configuration informationcontaining an indication of an absence of a PDCCH transmission to besent in the control channel search space set to indicate the identifiedtime and frequency resources for the PDSCH, and a set of time andfrequency resources for the control channel search space set. Theoperations of 1710 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1710 may beperformed by a configuration component as described with reference toFIGS. 9 through 12 .

At 1715 the base station 105 may transmit a PDSCH transmission in thefirst TTI using the identified time and frequency resources for thePDSCH. The operations of 1715 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1715may be performed by a physical channel component as described withreference to FIGS. 9 through 12 .

FIG. 18 shows a flowchart illustrating a method 1800 for virtual searchspace sets for beam indication in accordance with aspects of the presentdisclosure. The operations of method 1800 may be implemented by a basestation 105 or its components as described herein. For example, theoperations of method 1800 may be performed by a base stationcommunications manager as described with reference to FIGS. 9 through 12. In some examples, a base station 105 may execute a set of codes tocontrol the functional elements of the device to perform the functionsdescribed below. Additionally or alternatively, the base station 105 mayperform aspects of the functions described below using special-purposehardware.

At 1805 the base station 105 may identify time and frequency resourcesfor a PDSCH to be transmitted to a UE in a first TTI. The operations of1805 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1805 may be performed bya resource component as described with reference to FIGS. 9 through 12 .

At 1810 the base station 105 may transmit, to the UE, configurationinformation for a control channel search space set in a second TTI, thesecond TTI preceding the first TTI, and the configuration informationcontaining an indication of an absence of a PDCCH transmission to besent in the control channel search space set to indicate the identifiedtime and frequency resources for the PDSCH, and a set of time andfrequency resources for the control channel search space set. Theoperations of 1810 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1810 may beperformed by a configuration component as described with reference toFIGS. 9 through 12 .

At 1815, the base station 105 may transmit a TCI state in a field of aDCI. The operations of 1815 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1815may be performed by a physical channel component as described withreference to FIGS. 9 through 12 .

At 1820 the base station 105 may transmit the PDSCH transmission in theidentified time and frequency resources using a beam associated with thetransmitted TCI state based on a scheduling offset of the PDSCHtransmission being greater than or equal to a threshold value. Theoperations of 1820 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1820 may beperformed by a physical channel component as described with reference toFIGS. 9 through 12 .

FIG. 19 shows a flowchart illustrating a method 1900 for virtual searchspace sets for beam indication in accordance with aspects of the presentdisclosure. The operations of method 1900 may be implemented by a basestation 105 or its components as described herein. For example, theoperations of method 1900 may be performed by a base stationcommunications manager as described with reference to FIGS. 9 through 12. In some examples, a base station 105 may execute a set of codes tocontrol the functional elements of the device to perform the functionsdescribed below. Additionally or alternatively, the base station 105 mayperform aspects of the functions described below using special-purposehardware.

At 1905 the base station 105 may identify time and frequency resourcesfor a PDSCH to be transmitted to a UE in a first TTI. The operations of1905 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1905 may be performed bya resource component as described with reference to FIGS. 9 through 12 .

At 1910 the base station 105 may transmit, to the UE, configurationinformation for a control channel search space set in a second TTI, thesecond TTI preceding the first TTI, and the configuration informationcontaining an indication of an absence of a PDCCH transmission to besent in the control channel search space set to indicate the identifiedtime and frequency resources for the PDSCH, and a set of time andfrequency resources for the control channel search space set. Theoperations of 1910 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1810 may beperformed by a configuration component as described with reference toFIGS. 9 through 12 .

At 1915 the base station 105 may transmit a TCI state in a field of aDCI. The operations of 1915 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1915may be performed by a physical channel component as described withreference to FIGS. 9 through 12 .

At 1920 the base station 105 may transmit the PDSCH transmission in theidentified time and frequency resources using a first beam associatedwith a second TCI state based on a scheduling offset of the PDSCHtransmission being less than or equal to a threshold value, the firstbeam different from a second beam associated with the first TCI state,and the second TCI state of a control resource set associated with thecontrol channel search space set. The operations of 1920 may beperformed according to the methods described herein. In certainexamples, aspects of the operations of 1920 may be performed by aphysical channel component as described with reference to FIGS. 9through 12 .

It should be noted that the methods described above describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and other systems.A CDMA system may implement a radio technology such as CDMA2000,Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000,IS-95, and IS-856 standards. IS-2000 Releases may be commonly referredto as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to asCDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM).

An OFDMA system may implement a radio technology such as Ultra MobileBroadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical andElectronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are releasesof UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR,and GSM are described in documents from the organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above as well as other systemsand radio technologies. While aspects of an LTE, LTE-A, LTE-A Pro, or NRsystem may be described for purposes of example, and LTE, LTE-A, LTE-APro, or NR terminology may be used in much of the description, thetechniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro,or NR applications.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEs115 with service subscriptions with the network provider. A small cellmay be associated with a lower-powered base station 105, as comparedwith a macro cell, and a small cell may operate in the same or different(e.g., licensed, unlicensed, etc.) frequency bands as macro cells. Smallcells may include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs 115 with servicesubscriptions with the network provider. A femto cell may also cover asmall geographic area (e.g., a home) and may provide restricted accessby UEs 115 having an association with the femto cell (e.g., UEs 115 in aclosed subscriber group (CSG), UEs 115 for users in the home, and thelike). An eNB for a macro cell may be referred to as a macro eNB. An eNBfor a small cell may be referred to as a small cell eNB, a pico eNB, afemto eNB, or a home eNB. An eNB may support one or multiple (e.g., two,three, four, and the like) cells, and may also support communicationsusing one or multiple component carriers.

The wireless communications system 100 or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations 105 may have similar frame timing, andtransmissions from different base stations 105 may be approximatelyaligned in time. For asynchronous operation, the base stations 105 mayhave different frame timing, and transmissions from different basestations 105 may not be aligned in time. The techniques described hereinmay be used for either synchronous or asynchronous operations.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), anapplication-specific integrated circuit (ASIC), a field-programmablegate array (FPGA) or other programmable logic device (PLD), discretegate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media mayinclude random-access memory (RAM), read-only memory (ROM), electricallyerasable programmable read only memory (EEPROM), flash memory, compactdisk (CD) ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other non-transitory medium thatcan be used to carry or store desired program code means in the form ofinstructions or data structures and that can be accessed by ageneral-purpose or special-purpose computer, or a general-purpose orspecial-purpose processor. Also, any connection is properly termed acomputer-readable medium. For example, if the software is transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, digital subscriber line (DSL), orwireless technologies such as infrared, radio, and microwave, then thecoaxial cable, fiber optic cable, twisted pair, DSL, or wirelesstechnologies such as infrared, radio, and microwave are included in thedefinition of medium. Disk and disc, as used herein, include CD, laserdisc, optical disc, digital versatile disc (DVD), floppy disk andBlu-ray disc where disks usually reproduce data magnetically, whilediscs reproduce data optically with lasers. Combinations of the aboveare also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an exemplary step that is described as “based on conditionA” may be based on both a condition A and a condition B withoutdeparting from the scope of the present disclosure. In other words, asused herein, the phrase “based on” shall be construed in the same manneras the phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein, but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communication at a basestation, comprising: identifying time and frequency resources for aphysical downlink shared channel (PDSCH) to be transmitted to a userequipment (UE) in a first transmission time interval (TTI);transmitting, to the UE, configuration information for a control channelsearch space set in a second TTI, the second TTI preceding the firstTTI, and the configuration information comprising an indication of anabsence of a physical downlink control channel (PDCCH) transmission tobe sent in the control channel search space set to indicate theidentified time and frequency resources for the PDSCH, and a set of timeand frequency resources for the control channel search space set; andtransmitting a PDSCH transmission in the first TTI using the identifiedtime and frequency resources for the PDSCH.
 2. The method of claim 1,further comprising: transmitting the configuration information for thecontrol channel search space set using radio resource control signaling.3. The method of claim 1, wherein the configuration informationcomprises a control resource set configuration, a transmissionconfiguration indication (TCI) state, and the time and frequencyresources corresponding to resources of the control resource setconfiguration.
 4. The method of claim 1, further comprising:transmitting, in a field of a downlink control information (DCI), atransmission configuration indication (TCI) state, wherein the TCI statecomprises a spatial quasi-collocation (QCL) parameter for a beamindication.
 5. The method of claim 1, further comprising: transmitting,in a field of a downlink control information (DCI), a transmissionconfiguration indication (TCI) state; and transmitting, based at leastin part on a scheduling offset of the PDSCH transmission being greaterthan or equal to a threshold value, the PDSCH transmission in theidentified time and frequency resources using a beam associated with thetransmitted TCI state.
 6. The method of claim 1, further comprising:transmitting, in a field of a downlink control information (DCI), afirst transmission configuration indication (TCI) state; andtransmitting, based at least in part on a scheduling offset of the PDSCHtransmission being less than or equal to a threshold value, the PDSCHtransmission in the identified time and frequency resources using afirst beam associated with a second TCI state, the first beam differentfrom a second beam associated with the first TCI state, and the secondTCI state of a control resource set associated with the control channelsearch space set.
 7. The method of claim 1, wherein the control channelsearch space set associated with a control resource set comprises a zeronumber of PDCCH candidates.
 8. An apparatus for wireless communication,comprising: means for identifying time and frequency resources for aphysical downlink shared channel (PDSCH) to be transmitted to a userequipment (UE) in a first transmission time interval (TTI); means fortransmitting, to the UE, configuration information for a control channelsearch space set in a second TTI, the second TTI preceding the firstTTI, and the configuration information comprising an indication of anabsence of a physical downlink control channel (PDCCH) transmission tobe sent in the control channel search space set to indicate theidentified time and frequency resources for the PDSCH, and a set of timeand frequency resources for the control channel search space set; andmeans for transmitting a PDSCH transmission in the first TTI using theidentified time and frequency resources for the PDSCH.
 9. The apparatusof claim 8, further comprising: means for transmitting the configurationinformation for the control channel search space set using radioresource control signaling.
 10. The apparatus of claim 8, furthercomprising: means for transmitting, in a field of a downlink controlinformation (DCI), a transmission configuration indication (TCI) state,wherein the TCI state comprises a spatial quasi-collocation (QCL)parameter for a beam indication.
 11. The apparatus of claim 8, furthercomprising: means for transmitting the PDSCH transmission in the firstTTI using a beam corresponding to the identified time and frequencyresources based at least in part on a scheduling offset of the PDSCHtransmission being greater than or equal to a threshold value.
 12. Theapparatus of claim 8, further comprising: means for transmitting thePDSCH transmission in the first TTI using a first beam based at least inpart on a scheduling offset of the PDSCH transmission being less than orequal to a threshold value, the first beam different from a second beamcorresponding to the identified time and frequency resources.
 13. Anapparatus for wireless communication, comprising: a processor; memory inelectronic communication with the processor; and instructions stored inthe memory and executable by the processor to cause the apparatus to:identify time and frequency resources for a physical downlink sharedchannel (PDSCH) to be transmitted to a user equipment (UE) in a firsttransmission time interval (TTI); transmit, to the UE, configurationinformation for a control channel search space set in a second TTI, thesecond TTI preceding the first TTI, and the configuration informationcomprising an indication of an absence of a physical downlink controlchannel (PDCCH) transmission to be sent in the control channel searchspace set to indicate the identified time and frequency resources forthe PDSCH, and a set of time and frequency resources for the controlchannel search space set; and transmit a PDSCH transmission in the firstTTI using the identified time and frequency resources for the PDSCH. 14.The apparatus of claim 13, wherein the instructions are furtherexecutable by the processor to cause the apparatus to: transmit theconfiguration information for the control channel search space set usingradio resource control signaling.
 15. The apparatus of claim 13, whereinthe configuration information comprises a control resource setconfiguration, a transmission configuration indication (TCI) state, andthe time and frequency resources corresponding to resources of thecontrol resource set configuration.
 16. The apparatus of claim 13,wherein the instructions are further executable by the processor tocause the apparatus to: transmit, in a field of a downlink controlinformation (DCI), a transmission configuration indication (TCI) state,wherein the TCI state comprises a spatial quasi-collocation (QCL)parameter for a beam indication.
 17. The apparatus of claim 13, whereinthe instructions are further executable by the processor to cause theapparatus to: transmit, in a field of a downlink control information(DCI), a transmission configuration indication (TCI) state; andtransmit, based at least in part on a scheduling offset of the PDSCHtransmission being greater than or equal to a threshold value, the PDSCHtransmission in the identified time and frequency resources using a beamassociated with the transmitted TCI state.
 18. The apparatus of claim13, wherein the instructions are further executable by the processor tocause the apparatus to: transmit, in a field of a downlink controlinformation (DCI), a first transmission configuration indication (TCI)state; and transmit, based at least in part on a scheduling offset ofthe PDSCH transmission being less than or equal to a threshold value,the PDSCH transmission in the identified time and frequency resourcesusing a first beam associated with a second TCI state, the first beamdifferent from a second beam associated with the first TCI state, andthe second TCI state of a control resource set associated with thecontrol channel search space set.
 19. The apparatus of claim 13, whereinthe control channel search space set associated with a control resourceset comprises a zero number of PDCCH candidates.
 20. A non-transitorycomputer-readable medium storing code for wireless communication, thecode comprising instructions executable by a processor to: identify timeand frequency resources for a physical downlink shared channel (PDSCH)to be transmitted to a user equipment (UE) in a first transmission timeinterval (TTI); transmit, to the UE, configuration information for acontrol channel search space set in a second TTI, the second TTIpreceding the first TTI, and the configuration information comprising anindication of an absence of a physical downlink control channel (PDCCH)transmission to be sent in the control channel search space set toindicate the identified time and frequency resources for the PDSCH, anda set of time and frequency resources for the control channel searchspace set; and transmit a PDSCH transmission in the first TTI using theidentified time and frequency resources for the PDSCH.
 21. Thenon-transitory computer-readable medium of claim 20, wherein theinstructions are further executable to: transmit the configurationinformation for the control channel search space set using radioresource control signaling.
 22. The non-transitory computer-readablemedium of claim 20, wherein the configuration information comprises acontrol resource set configuration, a transmission configurationindication (TCI) state, and the time and frequency resourcescorresponding to resources of the control resource set configuration.23. The non-transitory computer-readable medium of claim 20, wherein theinstructions are further executable to: transmit, in a field of adownlink control information (DCI), a transmission configurationindication (TCI) state, wherein the TCI state comprises a spatialquasi-collocation (QCL) parameter for a beam indication.
 24. Thenon-transitory computer-readable medium of claim 20, wherein theinstructions are further executable to: transmit, in a field of adownlink control information (DCI), a transmission configurationindication (TCI) state; and transmit, based at least in part on ascheduling offset of the PDSCH transmission being greater than or equalto a threshold value, the PDSCH transmission in the identified time andfrequency resources using a beam associated with the transmitted TCIstate.
 25. The non-transitory computer-readable medium of claim 20,wherein the instructions are further executable to: transmit, in a fieldof a downlink control information (DCI), a first transmissionconfiguration indication (TCI) state; and transmit, based at least inpart on a scheduling offset of the PDSCH transmission being less than orequal to a threshold value, the PDSCH transmission in the identifiedtime and frequency resources using a first beam associated with a secondTCI state, the first beam different from a second beam associated withthe first TCI state, and the second TCI state of a control resource setassociated with the control channel search space set.
 26. Thenon-transitory computer-readable medium of claim 20, wherein the controlchannel search space set associated with a control resource setcomprises a zero number of PDCCH candidates.